Composite piston



March 10, 1931.

v. HUGHES COMPOSITE PISTON Filed March 1, 1928 Patented Mar. 10, 1931 UNITED STATES PATENT OFFICE 'VICTOR HUGHES, OF DETROIT, MICHIGAN, ASSIGNOR TO GENERAL MOTORS RESEARCH CORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OI DELAWARE.

COMPOSITE PISTON Application filed March i,

This invention relates to internal combustion engines and more particularly to an improvement in pistons which are adapted to reciprocate within the engine c linders.

It is one of the objects ot the invention to provide a piston of composite formation, which willbesimple in construction and of low cost, and which will have the combined advantages of freedom from strains, long wear, light weight and rapid heat dissipation.

Various other objects and advantages will be apparent from the following description taken in connection with the accompanying drawing wherein Figure l is a vertical sectional view of the piston embodying the present invention and is taken on line 1-1 oi Figure 2. Figure 2 is a similar sectional view taken at right angles to that of Figure l, as on line 2-2 in Figure 1. Figure 3 is a transverse sectional view on line 3-3 of Figure Ii. Figure 4: is a transverse sectional view ,on line H of Figure 2, and Figure 5 is a detail section illustrating the connection between two of the piston parts.

Referring by reference characters to the accompanying drawing, the numerals 11 indicate a pair of arcuate flexible sections preferalyv formed from sheet metal, each having a pair of lateral extensions or side portions 3, terminating in out-turned flanges or angular end portions 4. (last onto the end portions 4 are a pair of spaced piston pin bosses 5-5, depending from and forming an integral part of the piston head 6, having the usual ring grooves 7, and which consists of aluminum or other similar light weight metal having a relatively high coeflicient of expansion. Surrounding the bosses and arcuate sections 1 is a tubular sleeve or cylindrical skirt 8, formed from sheet steel or other ferrous metal, and which is carried by the arouate section, being welded or otherwise secured thereto at substantially diametrically opposite points spaced from the axis of the piston pin bosses.

To facilitate the union of the arcuate portions and skirt, two rows of bosses or teats 9 may be provided in the arcuate section, which are spot welded to the skirt.

From the above description, it will be seen 192a. Serial No. 258,424.

that the explosion forces are received by the aluminum head and transmitted directly through the dependent pin bosses to'the connecting rod, the skirt 8 being entirely relieved thereof, and servin the sole purpose of a guide or contact sur ace. Because of the low ooeificient of expansion of the steel skirt, the clearance to be provided between the walls of the cylinder and piston may be made quite I but one specific embodiment, it is to be understood that various modifications may be made, such as come within the scope of the appended claims.

Having thus described my invention, I claim:

1. A composite piston, including a shell of ferrous metal, an aluminum head therefor, having dependent piston pin bosses, and an inherently resilient tubular body carried by said bosses and to which said shell is attached.

2'. A piston, including a tubular skirt having a relatively low co-eficient of expansion a head having a relatively high co-eflicient of expansion and being rovided with integral dependent piston pin osses extending within the skirt, and a separately formed resilient tubular body carried by said bosses and secured to the skirt at substantially 90 from the' bosses.

3. A composite piston, including a skirt having a relatively low coelfi cient of expansion, a head therefor having a relatively high coefiicient of expansion, and provided with integral dependent piston pin bosses extending within said skirt, and a air of resilient arcuate elements secured to t e skirt at substantially diametrically opposite points, each of said elements having lateral portions secured to the piston pin bosses.

4. A composite piston, including a cast metal head having a relatively high coeflicient 5 of expansion and provided with a pair of dependent piston pin bosses, a pair of resillent arcuate sections each having a pair of lateral extensions provided with flanged extremities embedded within the respective 1o bosses, and a skirt having a relatively low coeflicient of expansion surroundin said bosses and secured to said arcuate sectlons at substantially diametrically opposite points, 90 from the axis of said piston pin bosses. 5. A piston including a tubular skirt, a head therefor separate from the skirt and provided with integral piston pin bosses that extend into the skirt, and a pair of resilient tie members of U shape in cross section, each having a portion thereof united with the skirt and having the legs thereof imbedded in the respective bosses. In testimony whereof I aifix my signature.

VICTOR HUGHES. 

